Abstract:

Solid-liquid two-phase flow is widely appeared in the coal chemical production process, two-phase solid-liquid flow erosion is a particular problem in the pipeline transportation system, and the potential for sudden system failure is extremely high and this has become a major hidden hazard for the safe production and stable operation of coal chemical plants. To reduce the production safety risk and ensure the safe and reliable operation of pipeline system, the study on the prediction of erosion life was a key part of the research on the integrity of coal chemical equipment. Taking a coal-water slurry vaporizer feed pipe of a coal chemical plant in Xinjiang as the research object, ANSYS 2012R1 software is applied to conduct numerical simulation analysis to determine the main location of the bend tube erosion and the erosion thinning in a short period of time, to provide the original sequence for the prediction model, and to establish GM(1,1) model, unbiased GM(1,1) model and gray Markov model respectively through gray prediction theory. The prediction of the erosion rate of the pipe bend was completed, and the service life and maintenance cycle of the pipe were derived by combining the “Assessment of corroded steel pipelines”. This showed that the erosion thinning was mainly concentrated in the axial direction of the bend about 70 degrees, and the maximum position of the erosion thinning did not move with the change of time under the same process conditions. The unbiased GM(1,1) model and the Gray Markov model had significant advantages in medium and long-term prediction, and the Gray Markov model was more suitable for long-term prediction work. The service life of the coal-water slurry vaporizer feed transfer bend involved was about 570 days, and the amount of erosion thinning increased significantly after the bend was put into service for 450 days, which required regular monitoring and preventive maintenance of the key parts of the bend.

Key words: two-phase flow, erosion, numerical simulation, grey prediction theory, life prediction

摘要：

固液两相流广泛出现在煤化工生产过程中，管道输送系统受固液两相流介质冲蚀磨损尤为严重，系统突发性失效风险极高，已成为煤化工装置安全生产与稳定运行的重大隐患。降低生产安全风险，保障管道系统安全可靠运行，开展冲蚀磨损寿命预测研究是煤化工设备完整性研究的关键一环。本文以新疆某煤化工企业水煤浆汽化炉进料管为研究对象，应用ANSYS 2021R1软件进行数值模拟分析，确定弯管冲蚀磨损主要位置与短期内冲蚀磨损减薄量，为预测模型建立提供原始序列，通过灰色预测理论分别建立GM(1,1)模型、无偏GM(1,1)模型以及灰色马尔科夫模型完成对弯管冲蚀速率的预测，并结合SY/T 6151—2009《钢质管道管体腐蚀损伤评价方法》得出该管道服役寿命与检修周期。结果表明：冲蚀磨损减薄主要集中在弯管轴向70°左右，且在工艺条件相同的情况下冲蚀磨损减薄的最大位置不随时间变化发生移动。无偏GM(1,1)模型与灰色马尔科夫模型在中长期预测中优势显著，且灰色马尔科夫模型更适宜长期预测工作。所涉及的水煤浆汽化炉进料输送弯管服役寿命为570天左右，在弯管投入使用450天后冲蚀减薄量增长显著，需要定期开展该弯管重点部位的监测与预防性维护。

关键词: 两相流, 冲蚀磨损, 数值模拟, 灰色预测系统, 寿命预测